Abstract

This thesis covers a comprehensive study on the estuarine set bag net (ESBN) fishery in Bangladesh using existing methods for fisheries management, sustainable livelihoods approach and local indigenous knowledge to explore the recommendations for the development of a better management plan. The study was carried out in the four coastal villages of Bangladesh, namely Charpara and Moheskhali villages in the Cox's Bazar district and Kattoli and Kumira villages in the Chittagong district. Total 64 types of species were found in the present investigation among which 48 were fishes, 10 were shrimps and the rest 6 were others aquatic
organisms. No significant differences were observed when fish, shrimp and others were compared with the month to month group wise distribution for the villages within the same districts while the differences were significant between villages from different districts. Two groups of months were identified through cluster analysis with
ward-linkage and correlation coefficient distances where one group consisted of the months from June to September while the other group included the months from October to May. The biodiversity indices also showed two distinct groups of months for fishes. However, the fish biodiversity indices showed significant differences between the villages Charpara and Moheskhali while no significant difference was observed between the villages Kattoli and Kumira. The shrimp biodiversity indices showed significant differences in the district wise village comparison. This findings conclude that the species assemblage of the ESBN fishery do not follow the same temporal and spatial distribution. High fishing mortality rates for the selected fish species were observed during the present study except for Bregmaceros mcclellandi which has a very few commercial value. Average fishing mortality (F) rate was found to be 4.28 yâ�»Â¹ with an average exploitation rate (E) 0.65. The virtual population
analysis showed that all the investigated fishes were being caught in their juvenile and pre adult stage. The relative yield per recruit and biomass per recruit analysis
suggested that the maximum exploitation rate for ESBN fishery ( Emax ) should be 0.42 with an average fishing mortality (Fmax) 2.42 yâ�»Â¹, which needs 60% reduction of the
present fishing pressure. The average catch per boat (CPB) per trip ranged between 15.32kg and 51.06kg indicating the variation in the CPB due to the location of the fishing area. A considerable difference in catch per net per trip was observed between the two investigated districts that were due to the size variation in the net as well as the distance in fishing area. Significant difference was also observed between the catch per person in different villages that pointed towards the absence of any fishing quota within the ESBN fishery. The range of CPB values indicated high level of over-fishing is occurring in the ESBN fishery of Bangladesh, as according to the Schaefer's model the maximum sustainable yield was found to be 4.58kg per boat per trip. The attributes for vulnerability study were selected through participatory methods in a 5-point likert scale and means of these attributes ranged between 4.15 and 4.54 indicating significant vulnerable situation is prevailing in the ESBN fishing community due to seasonality, shocks and trends. The headcount ratio ranged between 43% and 74% with an average 52%, which was higher compared to the national poverty line (37.4%) of Bangladesh. Livelihoods assets profiling showed that high level of poverty is prevailing in all the capital assets of the sustainable livelihoods approach. Poverty levels were quantified using fuzzy method and poverty values were found to be 0.64, 0.29, 0.66 and 0.55 for human poverty index, physical poverty
index, social poverty index and financial poverty index respectively. Among the four capital assets investigated, social and human poverty levels were found very much
acute in the fishermen community of Bangladesh. Fishermen's perception about their fishery was investigated through participatory methods and the means of the selected
attributes ranged between 3.61 and 4.79, which indicated that fishermen have a significant perception about their fishery. About 78.67% of the fishermen wanted to change their present occupation that reflected the extreme disappointing attitude of the fishermen regarding their fishery. The principle component analysis justified about
the grouping of the micro-variables into the composite attributes as well as the study of the participatory methods used in the present study. The Kaiser-Meyer-Olkin test
for sampling adequacy and Bartlett's test of sphericity also significantly justified about the use of principle component analysis. Depending on the present findings, the possible management recommendations for development of a management plan of the ESBN fishery of Bangladesh has been adopted which are both multidisciplinary and integrated.